In the general field of combat and commercial weaponry, there is a broad range of accessories available for mounting onto standard firearms in order to upgrade the capability of these weapons. Of particular interest in the context of upgrade accessories is the M16/M4 weapon system that is typically utilized in military or combat settings. Most new models of the M16/M4 weapons also include a dovetail rail interface integrally formed along the top of the upper receiver. This interface rail provides a convenient mounting point for many of the available accessories for use with the M16/M4 firearm, such as scopes, sighting devices, lasers, and directed fire devices. The barrel is held in assembled relation with the upper receiver by a barrel nut that is threaded onto the outside surface of the barrel-receiving receptacle.
Some commercially available after market arm rail/handguard assembly systems require permanent modification of the firearm, such as replacing the original barrel nut with a proprietary barrel nut design, before installation thereof, while others are compatible with the existing configuration of the barrel nut provided by the manufacturer. Either way, it is critical during the installation and use of the rail/handguard assembly that the alignment of the rail/handguard assembly longitudinally, axially, and radially relative to the axis of the barrel bore be free from slippage, canting, or other angular displacements, less accessories, such as scopes securable to the rail/handguard assembly not provide true aiming of the firearm.
It would therefore be useful to provide a modular rail assembly for use with a firearm that prevents any of longitudinal, axial, or radial misalignment of the modular rail assembly relative to the barrel of the firearm at the time of installation.
It would be further useful to provide a modular rail assembly for use with a firearm which prevents any of longitudinal, axial, or radial misalignment of the modular rail assembly relative to the barrel axis of the firearm during use.